Heat sink apparatus, blower for use therein and electronic equipment using the same apparatus

ABSTRACT

A blower is provided for effectively cooling heat generating parts in a casing of a personal computer and so on, with a heat sink apparatus using the blower and an electronic equipment using the heat sink apparatus. The blower comprises a fan and an outer frame. The outer frame of the fan is made of a highly thermally conductive material such as aluminum. A radiation board is fixed to or formed integrally with a lower surface of the outer frame. Heat generated from a heat generating device is conveyed through the radiation board to the outer frame. The blower is provided with radiation fins so that the heat conveyed to the outer frame is transferred to the radiation fins as well.

FIELD OF THE INVENTION

[0001] This invention relates to a blower for cooling heat generating parts in a casing of an electronic equipment such as a computer of desk-top type or portable or mobile type, and to a heat sink apparatus using the same blower.

DESCRIPTION OF THE RELATED ART

[0002] Followed by the recent tendency to large-scale integration and expedition, the amount of heat generated by the semiconductor such as a microprocessor unit (hereinafter, referred to as MPU) is increasing. In a personal computer and the like incorporating the MPU which generates a large amount of heat, there have been made various attempts such as to mount a heat sink for radiating heat or a heat sink having a built-in fan motor on an upper surface of the MPU for the purpose of suppressing a temperature rise in a casing.

[0003]FIG. 6 shows a dimensional relationship in a case where a heat sink having a built-in fan motor is mounted on an upper surface of the MPU. When the thicknesses of an MPU 71, a printed circuit board 72 and a heat sink 73 having a built-in fan motor are 6 mm, 2 mm and 18 mm respectively, the overall thickness is 26 mm in total. Considering suction of air by the fan motor and insulation of the back of the printed circuit board, there is needed a space of at least 40 mm or so.

[0004] In an electronic equipment such as a notebook personal computer or the like, which is required to be thin, an interior space is limited to 30 mm. For this reason, it is impossible to insure an ample space above the upper surface of the MPU on the printed circuit board, and therefore it is impossible to mount a heat sink having a built-in fan motor on the upper surface of the MPU, giving rise to a problem in thermal design.

[0005] Meanwhile, in a desk-top personal computer, it is possible to insure a space above the upper surface of the MPU on the printed circuit board, and however there are needed to fan motors for a fan on the MPU and for another fan for exhaust of air from the casing, giving rise to a problem in cost.

SUMMARY OF THE INVENTION

[0006] In view of the above problems, a heat sink apparatus according to the present invention has a thermally conductive outer frame having a fan disposed in an opening thereof, the outer frame being mounted at one end of a heat conduction member for conducting heat of a heat generating device so as to conduct the heat to the vicinity of the fan to cool the heat generating device. Further, there is provided a heat sink apparatus of the invention that radiation fins are provided on the outer frame to cool the heat generating device more efficiently.

[0007] Moreover, a blower according to the present invention provides with radiation fins having a fan drive section and a thermally conductivity on the side of a fan, adjacent to a heat generating device, within an opening of a thermally conductive outer frame, and therefore the blower can be made small size.

[0008] In addition, an electronic equipment according to the present invention includes a casing housing a circuit board having a heat generating device mounted thereon and a heat conduction member for conducting heat of the heat generating device therein, an outer frame having a thermally conductivity and providing with a fan disposed in an opening thereof, the outer frame being attached to the heat conduction member, and radiation fins having thermally conductivity and being provided on the outer frame, so as to remove the heat of the heat generating device through the heat conduction member, the outer frame and the fins.

[0009] With the above construction, the heat of the heat generating device is not only conducted and removed by making use of the outer frame of the fan and the radiation fins in the fan drive section but also cooled by the fan, and therefore the heat of the heat generating device can be removed effectively, and accordingly the equipment incorporating the heat generating device can be made smaller size.

BRIEF DESCRIPTION OF DRAWING

[0010]FIGS. 1A and 1B are perspective views of a blower according to the present invention;

[0011]FIG. 2 is a sectional view taken along the line II-II of FIG. 1;

[0012]FIG. 3 is a sectional view showing a construction of a heat sink apparatus in accordance with the invention;

[0013]FIG. 4 is a perspective view of an electronic equipment to which the heat sink apparatus of the invention is applied;

[0014]FIG. 5 is a sectional view taken along the line V-V of FIG. 4; and

[0015]FIG. 6 is a schematic side view of a conventional heat sink having a built-in fan motor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016]FIGS. 1A and 1B generally show a blower according to one embodiment of the present invention. FIG. 1A is a perspective view of the blower as viewed from the suction port side thereof, while FIG. 1B is a perspective view thereof from the exhaust port side thereof.

[0017] A blower 1 has an outer frame 3 made of a highly thermally conductive metal such as aluminum, copper or aluminum nitride. The outer frame 3 has an opening 5 in which a fan 7 is disposed. In the center of a suction port of the outer frame 3, a bearing portion 11 which supports a rotary shaft 9 of the fan 7 is formed integrally with the outer frame 3. On the suction port side of the outer frame 3, a pair of attaching portions 17, projecting from opposite side portions 13 of the outer frame 3 to extend beyond a suction surface 15, are formed integrally with the outer frame 3. In the vicinity of the suction port within the opening 5 of the outer frame 3, radiation fins 19 are formed integrally with the outer frame 3. The radiation fins 19 are arranged in the opening 5 thereof so as to surround the rotary shaft 9. One of the side portions 13 of the outer frame 3 is formed with a slit 21 through which a lead wire 23 for electric power source is led out. A lead holder 25 is inserted in the slit 21 to prevent the lead wire 23 from coming out of the slit 21. The radiation fins 19 may be formed separately from the outer frame 3 and fixed thereto by means of screws or the like.

[0018]FIG. 2 is a sectional view taken along the line II-II of FIG. 1.

[0019] The rotary shaft 9 is fitted to the bearing portion 11 through ball bearings 27, and the fan 7 is attached to one end of the rotary shaft 9. A rotor yoke 29 and a magnet 31 are fixed to an inside of the fan 7. A stator core 37 is attached to the bearing portion 11 within the opening 5. A coil 35 is wound around a stator core 37 by way of an insulator 39 to which a base plate 33 of a fan-driving circuit is mounted. An insulator 39 is disposed between the coil 35 and the stator core 37. The rotor yoke 29, the magnet 31, the fan base plate 33, the coil 35 and the stator core 37 constitute a drive section for rotating the fan.

[0020] The radiation fins 19 are provided on the side of the blower 1 where the drive section of the fan 7 is arranged, and therefore the blower 1 can be made smaller. Further, the radiation fins 19 are provided in the vicinity of the suction port of the blower 1, and therefore heat dissipation can be performed efficiently.

[0021]FIG. 3 shows a heat sink apparatus according to one embodiment of the present invention.

[0022] A micro-processor unit (hereinafter, referred to as MPU) 43, which is a heat generating device, is set on a lower surface of a printed circuit board 41. The heat generating device is not limited to the MPU but may be other semiconductor such as a power IC. The MPU 43 is mounted on the printed circuit board 41 at one surface thereof and thermally connected at the other surface thereof to a radiation board 47, which is a heat conduction member, through a radiation sheet 45 such as a silicon grease layer or a thermally conductive rubber sheet. Namely, the printed circuit board 41 and the radiation board 47 are fastened to each other with screw while leaving a predetermined space between them in such a manner that the heat of the MPU 43 is transferred to the radiation board 47. The radiation board 47 is made of a highly thermally conductive metal such as aluminum, copper or aluminum nitride. The radiation board 47 is formed at one end thereof with a mounting portion 49 to which the blower 1 is fixed. The attaching portion 17 of the blower 1 is fastened to the mounting portion 49 of the radiation board 47 by means of a screw 51. Namely, the blower 1 is fixed to the radiation board 47 in such a manner that the suction port of the blower 1 faces the MPU 43. A thermally conductive grease 53 is applied between the mounting portion 49 of the radiation board 47 and the attaching portion 17 of the blower 1 so as to increase the strength of thermal connection. The mounting portion 49 of the radiation board 47 and the attaching portion 17 of the blower 1 may be fastened to each other by other means such as soldering. Further, it is also possible to form the radiation board 47 and the outer frame of the blower 1 into one body by means of die casting or the like.

[0023] Heat generated from the MPU 43 is transfered through the radiation board 47 to the outer frame 3 and the radiation fins 19 of the blower 1. The radiation board 47, the outer frame 3 and the radiation fins 19 form a heat conduction path while each serving as a radiator device per se, thereby cooling the MPU 43. The outer frame 3 and the radiation fins 19 of the blower 1 are forcedly cooled by the fan 7, so that the radiation of heat can be effectively performed. Further, air currents produced by the fan 7 reach the MPU 43 and the radiation board 47 as well, and therefore the efficiency of radiation of heat from the surface of the MPU 43 and the radiation board 47 can be enhanced.

[0024] It is advisable that the radiation board 47 is formed in the shape of a plate, and however it is also possible to form a heat conduction member by making use of a heat pipe or the like.

[0025]FIG. 4 shows an electronic equipment according to one embodiment of the present invention.

[0026] A portable or mobile notebook personal computer 55 includes a base unit 57 which is a casing for housing a heat sink apparatus, and a display unit 59. The base unit 57 has a keyboard 61 on an upper surface thereof. The display unit 59 is connected to a rear portion of the upper surface of the base unit 57 in such a manner that it pivots freely with respect to the base unit 57. A liquid crystal display 63 is incorporated in the display unit 59. The base unit 57 is formed with an exhaust port 67 in one side surface 65 thereof.

[0027] This embodiment is a portable or mobile computer, and however the present invention is applicable to a desk-top computer, a word processor, a portable terminal equipment and so on.

[0028]FIG. 5 is a sectional view taken along the line V-V of FIG. 4.

[0029] A radiation board 69 as a heat conduction member is put on a bottom surface of a base unit 57 which constitutes the casing. A printed circuit board 71 is disposed above the radiation board 69 leaving a predetermined space between them. Both the radiation board 69 and the printed circuit board 71 are fastened to the base unit 57 by means of screws 73.

[0030] The printed circuit board 71 is formed in a predetermined portion thereof with a through hole 75. A projection 79 of a heat transfer block 77 serving as a heat transfer member, is inserted in the through hole 75 from below a lower surface of the printed circuit board 71. The heat transfer block 77 is made of a highly thermally conductive metal such as an aluminum alloy. The heat transfer block 77 is fixed to the printed circuit board 71 by means of screws 81.

[0031] A semiconductor chip 83 of tape-carrier-package type, or tape automated bonding type, which is a heat generating device, is put on an upper surface of the projection 79 of the heat transfer block 77. The semiconductor chip 83 is fixed to the upper surface of the projection 79 by means of an electrically conductive bonding agent 85. A lower surface of the heat transfer block 77 is thermally connected to the radiation board 69 through a radiation sheet 87.

[0032] The radiation board 69 is provided at one end portion thereof, adjacent to the exhaust port 67, with a mounting portion 89 to which the attaching portion 17 of the blower 1 is fixed by means of a screw 91. A thermally conductive grease 93 is applied between the mounting portion 89 of the radiation board 69 and the attaching portion 17 of the blower 1 so as to enhance the efficiency of heat conduction between the mounting portion 89 and the attaching portion 17. The attaching portion 17 of the blower 1 is fixed to the mounting portion 89 of the radiation board 69, and therefore the suction port of the blower 1 faces the semiconductor chip 83 while the exhaust port of the blower 1 faces the exhaust port 67 of the base unit 57. Heat generated from the semiconductor chip 83 put on the upper surface of the printed circuit board 71 is transferred by the heat transfer block 77 to the lower surface side of the printed circuit board 71, and further transferred through the radiation sheet 87, the radiation board 69, the mounting portion 89 and the attaching portion 17 to the outer frame 3 and the radiation fins 19 of the blower 1. The radiation board 69 and the outer frame 3 and the radiation fins 19 of the blower 1 form a heat conduction path while each serving as a radiator per se, thereby cooling the semiconductor chip 83. The outer frame 3 and the radiation fins 19 are forcedly cooled by the fan 7, and therefore the radiation of heat can be effectively performed. Further, air currents produced by the fan 7 reach the semiconductor chip 83 and the radiation board 69 as well, and accordingly the efficiency of radiation of heat from the surfaces of the semiconductor chip 83 and the radiation board 69 can be enhanced.

[0033] In this embodiment, the heat transfer block 77 is inserted in the through hole 75 of the printed circuit board 71, and therefore the heat generated at the upper surface of the printed circuit board 71 can be transferred from the lower surface side of the printed circuit board 71 to the blower 1.

[0034] In this embodiment, the heat transfer block 77 is inserted in the through hole 75, and however it is also possible to transfer the heat from the upper surface to the lower surface of the printed circuit board 71 by using a plated through hole alone. Further, the radiation board 69 as the heat conduction member is used in this embodiment, and however it is also possible to transfer the heat to the blower by making use of a heat pipe or the like.

[0035] As has been described above, according to the present invention, the radiation fins are provided on the fan drive section side, and therefore the blower can be made small size. Further, the outer frame of the blower is made of a thermally conductive material and thermally connected to the heat conduction member, and therefore it is possible to materialize a heat sink apparatus and an electronic equipment which are compact and achieve high efficiency of heat radiation. 

What is claimed is:
 1. A heat sink apparatus comprising: an outer frame having an opening; a fan disposed in the opening of said outer frame; a drive section for rotating said fan; and a mounting member on which said outer frame and a heat generating device are provided, wherein said mount member includes a thermally conductive material.
 2. A heat sink apparatus according to claim 1, wherein said outer frame includes a thermally conductive material.
 3. A heat sink apparatus according to claim 1 or 2, wherein said heat generating device is a semiconductor device.
 4. A heat sink apparatus according to any one of claims 1, 2 and 3, wherein said outer frame and said fan are fixed to said mounting member in such a manner as to supply air substantially parallel to said mounting member.
 5. A heat sink apparatus comprising: an outer frame having an opening; a fan disposed in the opening of said outer frame; a drive section for rotating said fan; fins provided vertically on said outer frame; and a mounting member on which said outer frame and a heat generating device are fixed, wherein said mounting member includes a thermally conductive material.
 6. A heat sink apparatus comprising: an outer frame made of a thermally conductive material and having an opening; a fan disposed in the opening of said outer frame; a drive section for rotating said fan; fins provided vertically on said outer frame; and a mounting member on which said outer frame and a heat generating device are fixed, wherein said mounting member includes a thermally conductive material.
 7. A heat sink apparatus according to any one of claims 1, 2, 3, 4, 5 and 6, wherein a thermally conductive grease is applied between said mount member and said outer frame.
 8. A heat sink apparatus according to any one of claims 5, 6 and 7, wherein said fin is provided on the heat generating device side of said fan within said opening.
 9. A heat sink apparatus according to any one of claims 5, 6, 7 and 8, wherein said drive section comprises a rotary shaft projecting toward said heat generating device, and said fins are so disposed as to surround said rotary shaft.
 10. A heat sink apparatus according to any one of claims 5, 6, 7, 8 and 9, wherein said fins are formed integrally with said outer frame.
 11. A heat sink apparatus according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, wherein said drive section is provided on the heat generating device side of said fan within said opening.
 12. A heat sink apparatus according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, wherein said mounting member is formed in the shape of a plate.
 13. A heat sink apparatus for radiating heat of a heat generating device mounted on a circuit board, said apparatus comprising: a heat conduction member for conducting heat of said heat generating device, said member having a mounting portion at one end thereof; a thermally conductive outer frame having an opening and fixed to said mounting portion in such a manner that said opening faces said heat generating device; a fan disposed in said opening; a drive section for driving said fan; and thermally conductive radiation fins provided on said outer frame.
 14. A heat sink apparatus according to claim 13, wherein said heat generating device is a semiconductor device.
 15. A heat sink apparatus according to claim 13 or 14, wherein said radiation fins are formed integrally with said outer frame.
 16. A heat sink apparatus according to any one of claims 13, 14 and 15, wherein a thermally conductive grease is applied between said outer frame and said mounting portion.
 17. A heat sink apparatus according to any one of claims 13, 14, 15 and 16, wherein said radiation fins are provided on the heat generating device side of said fan within said opening.
 18. A heat sink apparatus according to claim 13 or 14, wherein said drive section is provided on the heat generating device side of said fan within said opening.
 19. A heat sink apparatus according to any one of claims 13, 14, 15, 16, 17 and 18, wherein said drive section comprises a rotary shaft projecting toward said heat generating device, and said radiation fins are so disposed as to surround said rotary shaft.
 20. A heat sink apparatus according to any one of claims 13, 14, 15, 16, 17, 18 and 19, wherein said heat conduction member is formed in the shape of a plate.
 21. A blower comprising: a thermally conductive outer frame having a suction port and an exhaust port; a fan disposed in the vicinity of said exhaust port; a drive section provided on the suction port side of said fan within said outer frame for rotating said fan; and thermally conductive radiation fins provided in the vicinity of said suction port and thermally connected to said outer frame.
 22. A blower according to claim 21, wherein said drive section comprises a rotary shaft projecting toward said suction port, and said radiation fins are so disposed as to surround said rotary shaft.
 23. A blower for supplying cool air to a heat generating device, said blower comprising: a thermally conductive outer frame having an opening; a fan disposed in said opening; a drive section provided on the heat generating device side of said fan within said opening for driving said fan; and thermally conductive radiation fins provided on the heat generating device side of said drive section within said opening and thermally connected to said outer frame.
 24. A blower according to claim 23, wherein said drive section comprises a rotary shaft projecting toward said heat generating device, and said radiation fins are so disposed as to surround said rotary shaft.
 25. A blower according to any one of claims 21, 22, 23 and 24, wherein said radiation fins are formed integrally with said outer frame.
 26. An electronic equipment comprising: a circuit board having a heat generating device mounted thereon; a heat conduction member having a mounting portion at one end thereof and serving to conduct heat of said heat generating device; a casing housing said circuit board and said heat conduction member and having an exhaust port in a potion thereof facing said mounting portion; a thermally conductive outer frame having an opening and fixed to said mounting portion in such a manner that said opening faces to said heat generating device and said exhaust port; a fan disposed in said opening; a drive section for driving said fan; and thermally conductive radiation fins provided on said outer frame.
 27. An electronic equipment according to claim 26, wherein said heat conduction member is thermally connected to an upper portion of said heat generating device.
 28. An electronic equipment according to claim 26 or 27, wherein said heat conduction member is thermally connected to an upper surface of said heat generating device through a radiation sheet.
 29. An electronic equipment according to claim 26, wherein said heat conduction member is thermally connected to said heat generating device at the surface of said circuit board opposite to a surface thereof on which said heat generating device is mounted.
 30. An electronic equipment comprising: a circuit board having a first surface, a second surface opposite to said first surface and a through hole formed to extend from said first surface to said second surface; a heat generating device disposed on said first surface above said through hole; a heat conduction member having a mounting portion at one end thereof and provided on the side of said second surface for conducting heat of said generating device; a casing housing said circuit board and said heat conduction member and having an exhaust port in an portion thereof facing said mounting portion; a thermally conduction outer frame having an opening and fixed to said mounting portion in such a manner that said opening faces said heat generating device and said exhaust port; a fan disposed in said opening; a drive section for driving said fan; and thermally conductive radiation fins provided on said outer frame.
 31. An electronic equipment according to claim 30, wherein said heat conduction member is disposed at a predetermined distance from said second surface.
 32. An electronic equipment according to claim 30 or 31, wherein a thermally conductive heat transfer member is provided in said through hole, said heat transfer member being thermally connected to said heat generating device and said heat conduction member.
 33. An electronic equipment according to claim 30, wherein said heat transfer member is thermally connected to said heat conduction member through a radiation sheet.
 34. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32 and 33, wherein said radiation fins are formed integrally with said outer frame.
 35. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32, 33 and 34, wherein a thermally conductive grease is applied between said outer frame and said mounting portion.
 36. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32, 33, 34 and 35, wherein said radiation fins are provided on the heat generating device side of said fan within said opening.
 37. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32, 33, 34, 35 and 36, wherein said drive section is provided on the heat generating device side of said fan within said opening.
 38. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36 and 37, wherein said drive section comprises a rotary shaft projecting toward said heat generating device, and said radiation fins are so disposed as to surround said rotary shaft.
 39. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 and 38, wherein said heat generating device is a semiconductor device.
 40. An electronic equipment according to any one of claims 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38 and 39, wherein said heat conduction member is formed in the shape of a plate and disposed in parallel relation to said circuit board. 